Elon Musk took aim at Twitter with a $43bn (about R631bn) cash offer on Thursday, with the Tesla CEO and billionaire entrepreneur saying the social media giant needs to be taken private to grow and become a platform for free speech.

“Twitter has extraordinary potential. I will unlock it,” Musk, who is already the company's second-largest shareholder, said in a letter to Twitter's board on Wednesday. The offer was made public in a regulatory filing on Thursday...